Seborrheic Keratosis

One of the most common types of non-cancerous (benign) skin growths, seborrheic keratoses (SKs) are often confused with warts or moles. Most people develop at least one seborrheic keratosis at some point in their lives.

What does Seborrheic Keratosis look like?

Ranging in size from a centimeter to more than a half-dollar in diameter, SKs are non-cancerous growths of the epidermis which sometimes appear in clusters or as one growth. They can vary in color from light tan to black, but they are usually brown. The common feature of SKs is their “pasted-on” appearance, sometimes looking like a dab of brown candle wax that has dropped and cooled onto the surface of the skin. Frequently located on the back or torso, SKs can also be found on the face, neck, scalp, or most other areas on the body. The growths usually begin one at a time as tiny, course, itchy bumps which eventually thicken and develop a wart-like surface. Removal may be recommended if they become large, irritated, itch, or bleed easily. Sometimes a SK may be difficult to distinguish from skin cancer because of its appearance.

How is Seborrheic Keratosis diagnosed?

Your doctor can usually diagnose seborrheic keratosis by inspecting the growth. After examination, your doctor may recommend a biopsy (removal for study under a microscope) to confirm the diagnosis or to rule out other skin conditions. Seborrheic keratoses do not become cancerous, but they can resemble skin cancer.

How is Seborrheic Keratosis treated?

Seborrheic keratosis usually requires no treatment and is normally painless. However, you may decide to have them removed for cosmetic reasons or if they become irritated. Your doctor can remove SKs through the following methods:

Electrosurgery - A local anesthesia is used to numb the SK growth and an electric current is used to burn it before being scraped off.

Cryosurgery - Liquid nitrogen, a very cold liquid gas, is applied to the SK growth with a spray gun or cotton swab to "freeze" it. After this, a blister forms below the SK growth. This blister dries up and the SK usually falls off in a few weeks.

Curettage - The area is numbed with an injection or spray before the SK growth is removed. Then, it is cut from the skin with a surgical instrument. Normally, a minimal amount of bleeding occurs and is controlled by the application of a blood-clotting chemical or by applying pressure.

How to prevent Seborrheic Keratosis

No ointments, creams, or other medications can cure or prevent SKs. Their exact cause is unclear. Genetics may play a role, as they tend to run in some families. They are common on sun-exposed areas, such as the back, arms, face and neck.